Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Material is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the mold cavity. After a product is designed, usually by an industrial designer or an engineer, molds are made by a moldmaker (or toolmaker) from metal, usually either steel or aluminum, and precision-machined to form the features of the desired part. Injection molding is widely used for manufacturing a variety of parts, from the smallest component to entire body panels of cars.
The art of molding machines used in injection molding is replete with various designs. One of such designs is taught by U.S. Pat. No. 4,521,172 to Gilbert. U.S. Pat. No. 4,521,172 to Gilbert teaches a press apparatus comprising two side frame members and a top plate between the side frame members and a lower table below the top plate. A fixed platen is mounted to the top plate. The platen is connected to the respective halves of a mold device. In all operational modes and when the press apparatus is not forming parts, the mold device applies additional weight to the top plate, which results in deflection and distortion of the top plate. The top plate deflected under the additional weight further results in offset between the respective halves of a mold device thereby forming defective parts.
Another prior art reference, such as U.S. Pat. No. 6,558,149 to Bodmer et al., for example, teaches an injection molding apparatus. A mold holding plate includes one of the injection molding mold halves. Similar to the U.S. Pat. No. 4,521,172 to Gilbert, the weight of the molding mold half applied to the mold holding plate results in deflection and distortion of the mold holding plate, which results in offset between the respective molding mold halves, which in return further results in defective parts formed by the injection molding apparatus.
Still another prior art reference, teaches a mold apparatus having a mold holding member and a pair of supports extending from the mold holding member to define a frame. A mold device for molding parts is positioned within the frame. A lifting device is connected to the frame and is positioned beyond the frame. The lifting device is also connected to the mold device as the mold device is hanging on the mold holding member.
In different operational modes, the lifting device moves the mold device to and away from the mold holding plate. In all operational modes and when the mold apparatus is not forming parts, the mold device applies additional weight to the mold holding member which results in deflection and distortion of the mold holding member, which results in offset between the first mold portion and the second mold portion thereby further resulting in defective parts formed by the mold apparatus.
Therefore, an opportunity exists for an improved molding apparatus for holding a mold assembly including first and second mold portions. Moreover, the opportunity exists for the molding machine configured to withstand deflection and distortion as the molding machine is in operational use with the mold assembly connected to and hanging from a top portion or a mold holding member of the molding machine thereby eliminating offset between the first mold portion and the second mold portion to prevent production of defective parts as the molding apparatus forms the parts.